On 25/02/13 08:55, Paolo Bonzini wrote:
>
>> Another thing is, that qdev_free looks now different, some days ago
>> it also did an unref. As far as I can see the object_unparent in
>> virtio-ccw was always the wrong thing to do.
>
> object_unparent is "almost" idempotent, i.e. idempotent as long as it does
> not cause the last reference to go away. So, doing an object_unparent
> before qdev_free was not wrong when qdev_free did an object_unref.
Hmm, the old sequence was
object_unparent(OBJECT(dev));
qdev_free(dev) ---+
|
V
...
object_unparent(OBJECT(dev)); now the last reference is gone,
object is freed
object_unref(OBJECT(dev)); now the reference of a deleted
object becomes -1
...
Isnt that a problem in itself that we modify a reference counter in an deleted
object?
>
> I think qdev_free is better, unless we want to change all of them
> at the same time.
Ok, so we leave the patch as is.
Christian
